It is believed to be nutritionally advantageous to provide nutritional products for human newborns and infants which have a ratio of calcium to phosphorus that mimics the ratio in human milk. Condensed skim bovine milk is often used as a source of protein in such nutritional products, but naturally contains more phosphorus than is desired in such products. There is provided in accordance with the present invention a method of using ion exchange technology to remove phosphorus from mammalian milk to alter the ratio of calcium to phosphorus in the milk.